Enzymes (Cambridge International IGCSE Science)

What Are Enzymes?

• Enzymes are:

  • Catalysts that speed up the rate of a chemical reaction without being changed or used up in the reaction

  • Proteins

  • Biological catalysts

    • Biological because they are made in living cells
    • Catalysts because they speed up the rate of chemical reactions without being changed

  • Necessary to all living organisms as they maintain reaction speeds of all metabolic reactions (all the reactions that keep an organism alive) at a rate that can sustain life

    • For example, if we did not produce digestive enzymes, it would take around 2 - 3 weeks to digest one meal; with enzymes, it takes around 4 hours